The buyers include South Korea's Posco, the world's fifth largest steel maker, The New York Times reported Wednesday.
It also includes Taiwanese firm China Steel and South Korean investment group EQ Partners.
ArcelorMittal has been paring down its assets, selling $4.2 billion worth of assets in the past 16 months in order to keep up with debt payments during the economic downturn, which has reduced its sales in Europe by 30 percent compared with 2007, the Times said.
The sale announced Wednesday involves some of the firm's more promising iron ore mines. It produces 40 percent of Canada's iron ore, the company said.
But ArcelorMittal shares rose 3.9 percent in early trading in European markets, a sign that investors thought the firm got a good price for the 15 percent of the operation it sold. AccelorMittal will retain 85 percent of the unit, which the deal values at $7.3 billion.